A thermal interface adhesive and method of making the same

Abstract

The application discloses a kind of thermal interface adhesive and preparation method thereof.The main component of the thermal interface adhesive is diamond nanofiber, polysaccharide molecule, adhesive matrix, amphiphilic compatibilizer and thermal conductive filler, diamond nanofiber with high thermal conductivity and easy to form network structure is used as the matrix structure of hydrogel;Add amphiphilic compatibilizer to improve the compatibility between diamond nanofiber and polysaccharide molecule and adhesive matrix;Diamond nanorod surface modified by ferrocene derivative capable of effectively improving the thermal conductivity of adhesive is used as thermal conductive filler, and flow cold casting method is used to prepare thermal interface adhesive with high adhesion and high thermal conductivity.Using flow cold casting method can more effectively keep the nanofiller inside the adhesive evenly dispersed and orderly oriented, to avoid the agglomeration of nanofiller.

Description

Technical Field

[0001] This invention relates to the field of hydrogel technology, and more specifically to a thermal interface adhesive and its preparation method. Background Technology

[0002] With the continuous development of industrial technology, heat transfer devices such as heat exchangers, steam generators, and condensers are becoming increasingly common in industrial production. These devices are typically made of materials such as metals and ceramics, and their main function is to transfer heat from one medium to another. However, due to harsh working environments, these devices may suffer damage such as corrosion, wear, and cracks, leading to decreased heat transfer efficiency or even failure. To repair this damage, traditional methods usually involve replacing damaged parts or performing welding repairs, but both methods have some problems: replacing parts requires downtime for maintenance, which is time-consuming and costly; while welding repairs may cause secondary damage or even lead to equipment failure.

[0003] Therefore, developing a method for rapidly and efficiently repairing damage to heat transfer devices is of significant practical importance. Viscous hydrogels, with their viscosity and fluidity, can form a sealing layer at the damage site to repair devices, attracting widespread attention. Commercially available hydrogels widely use polymers as the matrix. While this effectively ensures the hydrogel's extensibility and flexibility, it also inherits the low thermal conductivity of polymer molecules, which is detrimental to the heat transfer function of the repaired device. Currently, a common method to improve the thermal conductivity of hydrogels is to add nano-inorganic fillers; however, due to the tendency of nano-fillers to aggregate, the addition of inorganic fillers may adversely affect the thermal conductivity of the hydrogel.

[0004] Due to the low thermal conductivity of polymer hydrogels, traditional polymer hydrogels used in the market may cause excessively high local temperatures in the repaired thermal pathways, ultimately damaging the electronic thermal management system. Therefore, overcoming the low thermal conductivity of hydrogels while maintaining their strong adhesion has gradually become a research hotspot. The key to this research topic lies in how to enhance the thermal conductivity and adhesion of the hydrogel itself while preventing the aggregation and precipitation of inorganic fillers within the hydrogel. Summary of the Invention

[0005] The purpose of this invention is to provide a thermal interface adhesive with excellent thermal conductivity and mechanical properties, and its preparation method. This adhesive uses diamond nanofibers with high thermal conductivity and easy formation of a network structure as the matrix structure of the hydrogel; organic-inorganic compatibilizers are used to improve the compatibility between the diamond nanofibers and polysaccharide molecules and the adhesive matrix; and ferrocene derivative-modified diamond nanorods, which can effectively improve the thermal conductivity of the adhesive, are used as thermally conductive fillers.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a thermal interface adhesive, wherein the adhesive is a viscous hydrogel comprising diamond nanofibers, polysaccharide molecules, a viscous matrix having an orthophthalic polyphenol structure, a thermally conductive filler, and an amphiphilic compatibilizer, wherein the mass ratio of the diamond nanofibers, polysaccharide molecules, viscous matrix, and compatibilizer is (100–1500):(8–125):(8–125):(0.3–1.5), and the thermally conductive filler is a ferrocene derivative surface-modified diamond nanorod, wherein the mass ratio of the thermally conductive filler to the diamond nanofibers is (0.025–0.8):(1–15); and is prepared by a flow cold casting method.

[0008] Preferably, the polysaccharide molecule is selected from one of chondroitin sulfate, lentinan, and hyaluronic acid.

[0009] Preferably, the adhesive matrix is ​​selected from gallic acid, resveratrol, and cannabidiol. The catechol structure in the adhesive matrix can form multiple hydrogen bonds with the hydroxyl groups in the polysaccharide molecules, thereby improving the adhesion performance of the thermal interface adhesive.

[0010] Preferably, the compatibilizer is selected from one or more of octylphenol polyethylene ether, nonylphenol polyethylene ether, and decylphenol polyethylene ether. The compatibilizer can enhance the affinity between diamond nanofibers and other polar molecules.

[0011] Preferably, the preparation method of the ferrocene derivative surface-modified diamond nanorods is as follows: the surface carboxylated diamond nanorods are fully exposed in the ferrocene derivative, and the carbonyl groups on the surface of the diamond nanorods form hydrogen bonds with the ferrocene derivative, so that the ferrocene derivative is attached to the surface of the diamond nanorods.

[0012] Preferably, the ferrocene derivative is selected from one of ferrocene formaldehyde, ferrocene carboxylic acid, and ferrocene β-diketone.

[0013] Secondly, the present invention provides a method for preparing the above-mentioned thermal interface adhesive, comprising the following steps:

[0014] A. Preparation of hydrogel: Diamond nanofibers were dispersed in water, and polar-nonpolar compatibilizers, polysaccharide molecules, viscous matrix and ferrocene derivative surface-modified diamond nanorods were added sequentially under stirring. After stirring and mixing, the mixture was allowed to stand until it gelled, and a viscous hydrogel was initially obtained.

[0015] B. Flow-based cold casting process: 1. Flow film formation: The viscous hydrogel, after mixing to form a mobile phase, flows into the flow-based cold casting template through the flow channel to form a uniform film; 2. Magnetic field orientation: Under the action of a magnetic field in the vertical direction of the flow-based cold casting template, the ferrocene derivative surface-modified diamond nanorods undergo ordered orientation; 3. Freeze-direction: The ordered orientation of the diamond in the hydrogel is rapidly frozen and shaped by a low-temperature rapid cooling device at the end of the template flow channel, maintaining the regular arrangement of the diamond nanorods to obtain a thermal interface adhesive.

[0016] Preferably, the magnitude of the magnetic field in the fluid cold casting template described in step B is 2 × 10⁻⁶. -4 T~2×10 -1 T.

[0017] Preferably, the flow rate of the viscous hydrogel in the mobile phase in step B is 0.3 to 10 cm / s.

[0018] In this invention, the diamond nanofiber matrix ensures the adhesive possesses excellent thermal conductivity and mechanical properties. To overcome the adverse effects of the hydrophobicity of diamond nanofibers on the adhesive, an amphiphilic compatibilizer is added to the system, improving the compatibility of diamond nanofibers with other hydrophilic components. A tight multiple hydrogen bond structure is formed between the polysaccharide molecules and the viscous structure of the orthophthalic polyphenols in the adhesive. Compared to a single hydrogen bond structure, the multiple hydrogen bond structure enhances the cohesive force, adhesion, and morphological stability of the adhesive. The addition of diamond nanorods within the adhesive further improves its thermal conductivity, enabling it to exhibit good thermal conductivity when repairing damaged thermal pathways. Furthermore, by attaching ferrocene derivatives to the surface of the diamond nanorod filler, the diamond nanorod filler can be induced to orient under a magnetic field, forming an ordered structure and preventing the aggregation and precipitation of the diamond nanorods. Finally, the adhesive is rapidly frozen using a flow cold casting method. The resulting adhesive exhibits advantages such as high thermal conductivity, high mechanical strength, and strong adhesion.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) Compared with traditional polymer matrices, diamond nanofiber matrix can effectively improve the thermal conductivity and mechanical strength of adhesives, and the adhesives have a wider range of applications.

[0021] (2) The multiple hydrogen bond structure inside the thermal interface adhesive can provide stronger adhesion and mechanical properties compared with the hydrogen bond structure of traditional adhesives.

[0022] (3) Compared with traditional adhesive preparation methods, the flow cold casting method can more effectively maintain the uniform dispersion and orderly orientation of nanofillers inside the adhesive, and avoid the agglomeration of nanofillers. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the network structure of the viscous hydrogel matrix in an embodiment of the present invention; wherein component 1: diamond nanofibers, component 2: polysaccharide molecules, component 3: viscous matrix with ortho-phenyl polyphenol structure, and component 5: amphiphilic compatibilizer;

[0024] Figure 2 This is a schematic diagram of the magnetic field orientation principle of the viscous hydrogel in an embodiment of the present invention; wherein component 4: diamond nanorods, component 6: ferrocene derivative;

[0025] Figure 3 This is a schematic diagram of the viscous hydrogel flow cold casting method in an embodiment of the present invention, which is divided into three steps: step I: flow shaping, step II: magnetic field orientation, and step III: freezing orientation.

[0026] Figure 4 These are schematic diagrams illustrating the actual adhesion applications of the adhesives prepared in Examples 1-7 of this invention to the polypropylene plastic matrix.

[0027] Figure 5 This is a comparison of the bonding strength of the adhesive prepared in Example 2 of the present invention on various different substrates;

[0028] Figure 6 The temperature changes at the fracture points of the aluminum rods were compared after the adhesives and epoxy resin adhesives prepared in Examples 1 to 7 of this invention were used to repair the cross-section of the broken aluminum rods. Detailed Implementation

[0029] This invention provides a thermal interface adhesive, wherein the adhesive is a viscous hydrogel, and a schematic diagram of the viscous hydrogel matrix network structure is shown below. Figure 1 As shown, the viscous hydrogel matrix comprises diamond nanofibers (component 1), polysaccharide molecules within the hydrogel (component 2), a viscous matrix with an ortho-phenylene polyphenol structure within the hydrogel (component 3), and an amphiphilic compatibilizer within the hydrogel (component 5). Diamond nanofibers, which have high thermal conductivity and readily form a network structure, are used as the matrix structure of the hydrogel. The addition of the amphiphilic compatibilizer improves the compatibility between the diamond nanofibers, polysaccharide molecules, and the viscous matrix.

[0030] Diamond nanorods (component 4) are also added inside the hydrogel, dispersed within the hydrogel matrix. The surface of the diamond nanorods is modified with a ferrocene derivative (component 6). Under the influence of a magnetic field, the diamond nanorods modified with the ferrocene derivative undergo ordered orientation, such as... Figure 2 As shown.

[0031] The preparation process mainly consists of the following three steps, such as Figure 3As shown: Step I. Flow shaping: The mixed hydrogel is fed into the flow cold casting template via a conveyor belt in the flow channel, where it forms a thin film; Step II. Magnetic field orientation: Under the action of a magnetic field perpendicular to the flow cold casting template, the diamond nanorods modified with ferrocene derivatives in the hydrogel film undergo ordered orientation; Step III. Cryo-orientation: The ordered orientation of the diamond nanorods in the hydrogel is rapidly frozen and shaped using a low-temperature rapid cooling device at the end of the template flow channel, maintaining the regular arrangement of the diamond nanorods, ultimately yielding a thermal interface adhesive that combines high adhesion and high thermal conductivity.

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] Add 0.05g of surface carboxylated diamond nanorods and 0.1g of ferrocene carboxylic acid to beaker 1. Add a magnetic stir bar and stir thoroughly until no obvious diamond nanorod particles are observed in beaker 1. After standing for 12 hours, transfer the surface-modified diamond nanorods to a glass petri dish and vacuum dry for 6 hours for later use.

[0035] Weigh 1g of diamond nanofibers and place them in beaker 2. Add 30mL of deionized water and place a magnetic stir bar in the beaker. Then, use a pipette to add 3mL of a 1.25mg / mL amphiphilic compatibilizer octylphenol polyethylene ether solution to beaker 2. Place beaker 2 on a magnetic stir bar and stir until no aggregated diamond nanofibers are observed in beaker 2. After that, add 0.25g of chondroitin sulfate and 0.3g of gallic acid to beaker 2. Add 0.05g of ferrocene derivative surface-modified diamond nanorods to beaker 2, remove the magnetic stir bar in time, and let the mixture stand to allow it to gel, thus initially preparing a diamond nanorod modified viscous hydrogel.

[0036] Diamond nanorod-modified viscous hydrogel is placed on a horizontal conveyor belt and transported to the center of a flowing cold casting template. The conveyor belt speed is 2 cm / s, and the hydrogel flows in the flowing cold casting channel to form a thin film.

[0037] The conveyor belt transports the diamond nanorod modified hydrogel into a flowable cold casting template. The upper and lower sides of the center of the flowable cold casting template are distributed with a strength of 2×10⁻⁶. -4 The magnetic field T causes the ferrocene derivative-modified diamond nanorods inside the hydrogel to undergo ordered orientation.

[0038] Subsequently, a conveyor belt delivers the magnetically oriented diamond nanorod-modified viscous hydrogel to the outlet of a flowing cold-casting template. The outlet of the template is equipped with a liquid nitrogen pipe, which rapidly freezes the magnetically oriented diamond nanorod-modified viscous hydrogel flowing through it, maintaining the orientation of the diamond nanorods within the hydrogel. Once anchored at low temperature, the magnetically oriented diamond nanorods within the viscous hydrogel retain their orientation even after being removed from the induction effect of the magnetic field.

[0039] A thermal interface adhesive with high thermal conductivity and high adhesion was finally obtained. The thermal conductivity of the adhesive was measured to be 57.1 W / m² using a thermal constant analyzer. -1 K -1 The adhesive was subjected to an lap shear test using a universal testing machine, and the adhesion strength between the adhesive and the steel was measured to be 29.3 MPa. When the adhesive was bonded to a polypropylene plastic matrix, good adhesion between the adhesive and the polypropylene plastic was observed (e.g., ...). Figure 4 (As shown). The radially fractured 3003 aluminum rod was repaired using the aforementioned adhesive. The lower end of the aluminum rod was heated, and the temperature of the upper end of the aluminum rod was measured using an infrared thermometer. It was observed that the temperature change of the upper end of the aluminum rod over time was basically consistent with the temperature change of the upper end of the aluminum rod without radial fracture (e.g., Figure 6 (As shown).

[0040] Example 2

[0041] Add 0.025g of surface carboxylated diamond nanorods and 0.5g of ferrocene formaldehyde to beaker 1. Place a magnetic stir bar in the beaker and stir thoroughly until no obvious diamond nanorod particles are observed in beaker 1. After standing for 12 hours, transfer the surface-modified diamond nanorods to a glass petri dish and vacuum dry for 6 hours for later use.

[0042] Weigh 2g of diamond nanofibers and place them in beaker 2. Add 30mL of deionized water and place a magnetic stir bar in the beaker. Then, use a pipette to add 4mL of a 1.25mg / mL amphiphilic compatibilizer nonylphenol polyethylene ether solution to beaker 2. Place beaker 2 on a magnetic stir bar and stir until no aggregated diamond nanofibers are observed in beaker 2. After that, add 0.3g of hyaluronic acid and 0.2g of resveratrol to beaker 2. Add 0.025g of ferrocene derivative surface-modified diamond nanorods to beaker 2, remove the magnetic stir bar in time, and let the mixture stand to allow it to gel, thus initially preparing a diamond nanorod modified viscous hydrogel.

[0043] Diamond nanorod-modified viscous hydrogel is placed on a horizontal conveyor belt and transported to the center of a flowable cold casting template at a speed of 1 cm / s. The conveyor belt transports the diamond nanorod-modified hydrogel into the flowable cold casting template, where the hydrogel flows in the flowable cold casting channel to form a thin film.

[0044] The conveyor belt transports the diamond nanorod modified hydrogel into a flowable cold casting template. The upper and lower sides of the center of the flowable cold casting template are distributed with a strength of 2×10⁻⁶. -3 The magnetic field T causes the ferrocene derivative-modified diamond nanorods inside the hydrogel to orient themselves.

[0045] Subsequently, a conveyor belt delivers the magnetically oriented diamond nanorod-modified viscous hydrogel to the outlet of a flowing cold-casting template. The outlet of the template is equipped with a liquid nitrogen pipe, which rapidly freezes the magnetically oriented diamond nanorod-modified viscous hydrogel flowing through it, maintaining the orientation of the diamond nanorods within the hydrogel. Once anchored at low temperature, the magnetically oriented diamond nanorods within the viscous hydrogel retain their orientation even after being removed from the induction effect of the magnetic field.

[0046] A thermal interface adhesive with high thermal conductivity and high adhesion was finally obtained. The thermal conductivity of the adhesive was measured to be 52.7 W / m² using a thermal constant analyzer. -1 K -1 The adhesive was subjected to an lap shear test using a universal testing machine, and the adhesion strength between the adhesive and the steel was measured to be 30.7 MPa. The adhesive obtained in Example 2 was then subjected to lap shear tests with materials such as aluminum, brass, steel, wood, polypropylene, polytetrafluoroethylene, and polyethylene to obtain adhesion strength data between it and different substrates (e.g., ...). Figure 5 As shown); the adhesive was bonded to polypropylene plastic, and good adhesion between the adhesive and the polypropylene plastic was observed (as shown). Figure 4 (As shown). The radially fractured 3003 aluminum rod was repaired using the aforementioned adhesive. The lower end of the aluminum rod was heated, and the temperature of the upper end of the aluminum rod was measured using an infrared thermometer. It was observed that the temperature change of the upper end of the aluminum rod over time was basically consistent with the temperature change of the upper end of the aluminum rod without radial fracture (e.g., Figure 6 (As shown).

[0047] Example 3

[0048] Add 0.1g of surface carboxylated diamond nanorods and 0.5g of ferrocene β-diketone to beaker 1. Place a magnetic stir bar in the beaker and stir thoroughly until no obvious diamond nanorod particles are observed in beaker 1. After standing for 12 hours, transfer the surface-modified diamond nanorods to a glass petri dish and vacuum dry for 6 hours for later use.

[0049] Weigh 1.5g of diamond nanofibers and place them in beaker 2. Add 30mL of deionized water and place a magnetic stir bar in the beaker. Then, use a pipette to add 5mL of a 1.25mg / mL amphiphilic compatibilizer solution of decylphenol polyvinyl ether to beaker 2. Place beaker 2 on a magnetic stir bar and stir until no aggregated diamond nanofibers are observed in beaker 2. After that, add 0.15g of lentinan and 0.15g of cannabidiol to beaker 2. Add 0.1g of ferrocene derivative surface-modified diamond nanorods to beaker 2, remove the magnetic stir bar in time, and let the mixture stand to allow it to gel, thus initially preparing a diamond nanorod modified viscous hydrogel.

[0050] Diamond nanorod-modified viscous hydrogel is placed on a horizontal conveyor belt and transported to the center of a flowing cold casting template. The conveyor belt speed is 2.5 cm / s, and the hydrogel flows in the flowing cold casting channel to form a thin film.

[0051] The conveyor belt transports the diamond nanorod-modified hydrogel into the flowing cold casting template. The conveyor belt transports the diamond nanorod-modified hydrogel into the flowing cold casting template. The upper and lower sides of the center of the flowing cold casting template are distributed with a strength of 3×10... -5 The magnetic field T causes the ferrocene derivative-modified diamond nanorods inside the hydrogel to orient themselves.

[0052] Subsequently, a conveyor belt delivers the magnetically oriented diamond nanorod-modified viscous hydrogel to the outlet of a flowing cold-casting template. The outlet of the template is equipped with a liquid nitrogen pipe, which rapidly freezes the magnetically oriented diamond nanorod-modified viscous hydrogel flowing through it, maintaining the orientation of the diamond nanorods within the hydrogel. Once anchored at low temperature, the magnetically oriented diamond nanorods within the viscous hydrogel retain their orientation even after being removed from the induction effect of the magnetic field.

[0053] A thermal interface adhesive with high thermal conductivity and high adhesion was finally obtained. The thermal conductivity of the adhesive was measured to be 55.6 W / m² using a thermal constant analyzer. -1 K -1 The adhesive was subjected to an lap shear test using a universal testing machine, and the adhesion strength between the adhesive and the steel was measured to be 22.9 MPa. When the adhesive was bonded to polypropylene plastic, good adhesion was observed between the adhesive and the polypropylene plastic (e.g., ...). Figure 4 (As shown). The radially fractured 3003 aluminum rod was repaired using the aforementioned adhesive. The lower end of the aluminum rod was heated, and the temperature of the upper end of the aluminum rod was measured using an infrared thermometer. It was observed that the temperature change of the upper end of the aluminum rod over time was basically consistent with the temperature change of the upper end of the aluminum rod without radial fracture (e.g., Figure 6 (As shown).

[0054] Example 4

[0055] Add 0.5g of surface carboxylated diamond nanorods and 0.9g of ferrocene carboxylic acid to beaker 1. Add a magnetic stir bar and stir thoroughly until no obvious diamond nanorod particles are observed in beaker 1. After standing for 12 hours, transfer the surface-modified diamond nanorods to a glass petri dish and vacuum dry for 6 hours for later use.

[0056] Weigh 10g of diamond nanofibers and place them in beaker 2. Add 30mL of deionized water and a magnetic stir bar. Then, use a pipette to add 5mL of a 1.25mg / mL amphiphilic compatibilizer octylphenol polyethylene ether solution to beaker 2. Place beaker 2 on a magnetic stir bar and stir until no aggregated diamond nanofibers are observed in beaker 2. After that, add 0.15g of chondroitin sulfate and 0.13g of cannabidiol to beaker 2. Add 0.5g of ferrocene derivative surface-modified diamond nanorods to beaker 2, remove the magnetic stir bar immediately, and let the mixture stand to allow it to gel, thus initially preparing a diamond nanorod modified viscous hydrogel.

[0057] Diamond nanorod-modified viscous hydrogel is placed on a horizontal conveyor belt and transported to the center of a flowing cold casting template. The conveyor belt speed is 0.5 cm / s, and the hydrogel flows in the flowing cold casting channel to form a thin film.

[0058] The conveyor belt transports the diamond nanorod-modified hydrogel into the flowing cold casting template. The conveyor belt transports the diamond nanorod-modified hydrogel into the flowing cold casting template. The upper and lower sides of the center of the flowing cold casting template are distributed with a strength of 7×10... -3 The magnetic field T causes the ferrocene derivative-modified diamond nanorods inside the hydrogel to orient themselves.

[0059] Subsequently, a conveyor belt delivers the magnetically oriented diamond nanorod-modified viscous hydrogel to the outlet of a flowing cold-casting template. The outlet of the template is equipped with a liquid nitrogen pipe, which rapidly freezes the magnetically oriented diamond nanorod-modified viscous hydrogel flowing through it, maintaining the orientation of the diamond nanorods within the hydrogel. Once anchored at low temperature, the magnetically oriented diamond nanorods within the viscous hydrogel retain their orientation even after being removed from the induction effect of the magnetic field.

[0060] A thermal interface adhesive with high thermal conductivity and high adhesion was finally obtained. The thermal conductivity of the adhesive was measured to be 54.8 W / m² using a thermal constant analyzer. -1 K -1 The adhesive was subjected to an lap shear test using a universal testing machine, and the adhesion strength between the adhesive and the steel was measured to be 29.8 MPa. When the adhesive was bonded to polypropylene plastic, good adhesion was observed between the adhesive and the polypropylene plastic (e.g., ...). Figure 4 (As shown). The radially fractured 3003 aluminum rod was repaired using the aforementioned adhesive. The lower end of the aluminum rod was heated, and the temperature of the upper end of the aluminum rod was measured using an infrared thermometer. It was observed that the temperature change of the upper end of the aluminum rod over time was basically consistent with the temperature change of the upper end of the aluminum rod without radial fracture (e.g., Figure 6 (As shown).

[0061] Example 5

[0062] Add 0.8g of surface carboxylated diamond nanorods and 1.2g of ferrocene formaldehyde to beaker 1. Add a magnetic stir bar and stir thoroughly until no obvious diamond nanorod particles are observed in beaker 1. After standing for 12 hours, transfer the surface-modified diamond nanorods to a glass petri dish and vacuum dry for 6 hours for later use.

[0063] Weigh 15g of diamond nanofibers and place them in beaker 2. Add 30mL of deionized water and place a magnetic stir bar in the beaker. Then, use a pipette to add 10mL of a 1.25mg / mL amphiphilic compatibilizer nonylphenol polyethylene ether solution to beaker 2. Place beaker 2 on a magnetic stir bar and stir until no aggregated diamond nanofibers are observed in beaker 2. After that, add 1.25g of lentinan and 1.25g of resveratrol to beaker 2. Add 0.8g of ferrocene derivative surface-modified diamond nanorods to beaker 2, remove the magnetic stir bar in time, and let the mixture stand to allow it to gel, thus initially preparing a diamond nanorod modified viscous hydrogel.

[0064] Diamond nanorod-modified viscous hydrogel is placed on a horizontal conveyor belt and transported to the center of a flowing cold casting template. The conveyor belt speed is 0.8 cm / s, and the hydrogel flows in the flowing cold casting channel to form a thin film.

[0065] The conveyor belt transports the diamond nanorod-modified hydrogel into the flowing cold casting template. The conveyor belt transports the diamond nanorod-modified hydrogel into the flowing cold casting template. The upper and lower sides of the center of the flowing cold casting template are distributed with a strength of 8×10... -4 The magnetic field T causes the ferrocene derivative-modified diamond nanorods inside the hydrogel to orient themselves.

[0066] Subsequently, a conveyor belt delivers the magnetically oriented diamond nanorod-modified viscous hydrogel to the outlet of a flowing cold-casting template. The outlet of the template is equipped with a liquid nitrogen pipe, which rapidly freezes the magnetically oriented diamond nanorod-modified viscous hydrogel flowing through it, maintaining the orientation of the diamond nanorods within the hydrogel. Once anchored at low temperature, the magnetically oriented diamond nanorods within the viscous hydrogel retain their orientation even after being removed from the induction effect of the magnetic field.

[0067] A thermal interface adhesive with high thermal conductivity and high adhesion was finally obtained. The thermal conductivity of the adhesive was measured to be 52.8 W / m² using a thermal constant analyzer. -1 K -1 The adhesive was subjected to an lap shear test using a universal testing machine, and the adhesion strength between the adhesive and the steel was measured to be 27.4 MPa. When the adhesive was bonded to polypropylene plastic, good adhesion was observed between the adhesive and the polypropylene plastic (e.g., ...). Figure 4 (As shown). The radially fractured 3003 aluminum rod was repaired using the aforementioned adhesive. The lower end of the aluminum rod was heated, and the temperature of the upper end of the aluminum rod was measured using an infrared thermometer. It was observed that the temperature change of the upper end of the aluminum rod over time was basically consistent with the temperature change of the upper end of the aluminum rod without radial fracture (e.g., Figure 6 (As shown).

[0068] Example 6

[0069] Add 0.8g of surface carboxylated diamond nanorods and 1g of ferrocene formaldehyde to beaker 1. Stir thoroughly with a magnetic stir bar until no obvious diamond nanorod particles are observed in beaker 1. After standing for 12 hours, transfer the surface-modified diamond nanorods to a glass petri dish and vacuum dry for 6 hours for later use.

[0070] Weigh 5g of diamond nanofibers and place them in beaker 2. Add 30mL of deionized water and place a magnetic stir bar in the beaker. Then, use a pipette to add 3mL of a 1.25mg / mL amphiphilic compatibilizer solution of decylphenol polyvinyl ether to beaker 2. Place beaker 2 on a magnetic stir bar and stir until no aggregated diamond nanofibers are observed in beaker 2. After that, add 0.08g of hyaluronic acid and 0.08g of gallic acid to beaker 2. Add 0.8g of ferrocene derivative surface-modified diamond nanorods to beaker 2, remove the magnetic stir bar in time, and let the mixture stand to allow it to gel, thus initially preparing a diamond nanorod modified viscous hydrogel.

[0071] Diamond nanorod-modified viscous hydrogel is placed on a horizontal conveyor belt and transported to the center of a flowing cold casting template. The conveyor belt speed is 0.3 cm / s, and the hydrogel flows in the flowing cold casting channel to form a thin film.

[0072] The conveyor belt transports the diamond nanorod-modified hydrogel into the flowing cold casting template. The flowing cold casting template has diamond nanorod-modified hydrogel with a strength of 5×10⁻⁶ distributed on both the upper and lower sides of its center. -4 The magnetic field T causes the ferrocene derivative-modified diamond nanorods inside the hydrogel to orient themselves.

[0073] Subsequently, a conveyor belt delivers the magnetically oriented diamond nanorod-modified viscous hydrogel to the outlet of a flowing cold-casting template. The outlet of the template is equipped with a liquid nitrogen pipe, which rapidly freezes the magnetically oriented diamond nanorod-modified viscous hydrogel flowing through it, maintaining the orientation of the diamond nanorods within the hydrogel. Once anchored at low temperature, the magnetically oriented diamond nanorods within the viscous hydrogel retain their orientation even after being removed from the induction effect of the magnetic field.

[0074] A thermal interface adhesive with high thermal conductivity and high adhesion was finally obtained. The thermal conductivity of the adhesive was measured to be 53.9 W / m² using a thermal constant analyzer. -1 K -1 The adhesive was subjected to an lap shear test using a universal testing machine, and the adhesion strength between the adhesive and the steel was measured to be 27.9 MPa. When the adhesive was bonded to polypropylene plastic, good adhesion was observed between the adhesive and the polypropylene plastic (e.g., ...). Figure 4 (As shown). The radially fractured 3003 aluminum rod was repaired using the aforementioned adhesive. The lower end of the aluminum rod was heated, and the temperature of the upper end of the aluminum rod was measured using an infrared thermometer. It was observed that the temperature change of the upper end of the aluminum rod over time was basically consistent with the temperature change of the upper end of the aluminum rod without radial fracture (e.g., Figure 6 (As shown).

[0075] Example 7

[0076] Add 0.05g of surface carboxylated diamond nanorods and 0.2g of ferrocene β-diketone to beaker 1. Place a magnetic stir bar in the beaker and stir thoroughly until no obvious diamond nanorod particles are observed in beaker 1. After standing for 12 hours, transfer the surface-modified diamond nanorods to a glass petri dish and vacuum dry for 6 hours for later use.

[0077] Weigh 3g of diamond nanofibers and place them in beaker 2. Add 30mL of deionized water and place a magnetic stir bar in the beaker. Then, use a pipette to add 2.5mL of a 1.25mg / mL amphiphilic compatibilizer solution of decylphenol polyvinyl ether to beaker 2. Place beaker 2 on a magnetic stir bar and stir until no aggregated diamond nanofibers are observed in beaker 2. After that, add 0.5g of hyaluronic acid and 0.6g of resveratrol to beaker 2. Add 0.05g of ferrocene derivative surface-modified diamond nanorods to beaker 2, remove the magnetic stir bar in time, and let the mixture stand to allow it to gel, thus initially preparing a diamond nanorod modified viscous hydrogel.

[0078] Diamond nanorod-modified viscous hydrogel is placed on a horizontal conveyor belt and transported to the center of a flowing cold casting template. The conveyor belt speed is 10 cm / s, and the hydrogel flows in the flowing cold casting channel to form a thin film.

[0079] The conveyor belt transports the diamond nanorod-modified hydrogel into the flowing cold casting template. The conveyor belt transports the diamond nanorod-modified hydrogel into the flowing cold casting template. The upper and lower sides of the center of the flowing cold casting template are distributed with a strength of 1×10... -3 The magnetic field T causes the ferrocene derivative-modified diamond nanorods inside the hydrogel to orient themselves.

[0080] Subsequently, a conveyor belt delivers the magnetically oriented diamond nanorod-modified viscous hydrogel to the outlet of a flowing cold-casting template. The outlet of the template is equipped with a liquid nitrogen pipe, which rapidly freezes the magnetically oriented diamond nanorod-modified viscous hydrogel flowing through it, maintaining the orientation of the diamond nanorods within the hydrogel. Once anchored at low temperature, the magnetically oriented diamond nanorods within the viscous hydrogel retain their orientation even after being removed from the induction effect of the magnetic field.

[0081] A thermal interface adhesive with high thermal conductivity and high adhesion was finally obtained. The thermal conductivity of the adhesive was measured to be 56.1 W / m² using a thermal constant analyzer. -1 K -1 The adhesive was subjected to an lap shear test using a universal testing machine, and the adhesion strength between the adhesive and the steel was measured to be 28.3 MPa. When the adhesive was bonded to polypropylene plastic, good adhesion was observed between the adhesive and the polypropylene plastic (e.g., ...). Figure 4 (As shown). The radially fractured 3003 aluminum rod was repaired using the aforementioned adhesive. The lower end of the aluminum rod was heated, and the temperature of the upper end of the aluminum rod was measured using an infrared thermometer. It was observed that the temperature change of the upper end of the aluminum rod over time was basically consistent with the temperature change of the upper end of the aluminum rod without radial fracture (e.g., Figure 6 (As shown).

[0082] As shown in Table 1, compared with commonly available epoxy resin adhesives, the adhesive prepared in this invention has excellent adhesive strength and thermal conductivity.

[0083] Table 1 shows the thermal conductivity of the adhesive and the adhesion strength to the steel substrate in the examples.

[0084]

[0085]

[0086] In all embodiments, the adhesive prepared in Example 2 has the highest adhesive strength.

[0087] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A thermal interface adhesive, characterized in that, The adhesive is a viscous hydrogel, comprising diamond nanofibers, polysaccharide molecules, a viscous matrix, a thermally conductive filler, and an amphiphilic compatibilizer. The mass ratio of the diamond nanofibers, polysaccharide molecules, viscous matrix, and compatibilizer is (100–1500):(8–125):(8–125):(0.3–1.5). The thermally conductive filler is a ferrocene derivative surface-modified diamond nanorod, and the mass ratio of the thermally conductive filler to the diamond nanofiber is (0.025–0.8):(1–15). The viscous matrix is ​​selected from gallic acid, resveratrol, and cannabidiol. The compatibilizer is selected from one or more of octylphenol polyethylene ether, nonylphenol polyethylene ether, and decylphenol polyethylene ether. The adhesive is prepared by a flow cold casting method.

2. The thermal interface adhesive according to claim 1, characterized in that, The polysaccharide molecule is selected from one of chondroitin sulfate, lentinan, and hyaluronic acid.

3. The thermal interface adhesive according to claim 1, characterized in that, The preparation method of the ferrocene derivative surface-modified diamond nanorods is as follows: the surface carboxylated diamond nanorods are fully exposed in the ferrocene derivative, and the carbonyl groups on the surface of the diamond nanorods form hydrogen bonds with the ferrocene derivative, so that the ferrocene derivative is attached to the surface of the diamond nanorods.

4. The thermal interface adhesive according to claim 1, characterized in that, The ferrocene derivative is selected from one of ferrocene formaldehyde, ferrocene carboxylic acid, and ferrocene β-diketone.

5. A method for preparing a thermal interface adhesive according to any one of claims 1 to 4, characterized in that, Includes the following steps: A. Preparation of hydrogel: Diamond nanofibers were dispersed in water, and amphiphilic compatibilizer, polysaccharide molecules, viscous matrix and ferrocene derivative surface-modified diamond nanorods were added sequentially under stirring. After stirring and mixing, the mixture was allowed to stand until it gelled, and a viscous hydrogel was initially obtained. B. Flow casting process:

1. Flow film formation: The viscous hydrogel, which is mixed to form a mobile phase, is flowed into the flow casting template through the flow channel to form a uniform film; 2. Magnetic field orientation: Under the action of a magnetic field in the direction perpendicular to the flowing cold casting template, the diamond nanorods modified with ferrocene derivatives undergo ordered orientation.

3. Cryo-orientation: The diamond in the hydrogel is rapidly frozen and shaped in an ordered manner by a low-temperature rapid cooling device at the end of the template flow channel, maintaining the regular arrangement of the diamond nanorods to obtain a thermal interface adhesive.

6. The method for preparing the thermal interface adhesive according to claim 5, characterized in that, The magnitude of the magnetic field in the flowing cold casting template described in step B is 2 × 10⁻⁶. -4 T~2×10 -1 T.

7. The method for preparing the thermal interface adhesive according to claim 5, characterized in that, The flow rate of the viscous hydrogel in the mobile phase described in step B is 0.3–10 cm / s.

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